detail of a large crack in a rock spur.

bedrock boulder calcareous cave cavern cavernous clayey cliff cliffside coastline crack craggy crest crust crustal erode eroded erosion face foliation formation geologic geological geology grotto hole hollow indented jagged jaggy karstic layer limestone massif mineral mountain mountainside plate ridge rock rocks rocky rough seacoast seaside sediment sedimentary sheer shore shoreline spur steep stone stony tufa weathered weathering